Several million anesthetics are administered each year to an increasingly aging and hemodynamically unstable population. These anesthetic drugs have profound hemodynamic depressant effects. The specific anesthetic administered (among the several available drugs) for individual patients may have beneficial or deleterious effects on hemodynamics. In addition, the effects of catecholamine drugs (commonly administered with anesthetics) on the hemodynamic response to anesthetics has been investigated. These investigations examine the factors (and their interactions) that produce the hemodynamic response to anesthesia. Thus far, we have determined that individual effects interact with drug effects to produce the hemodynamic response. In a separate investigation, we found that these individual effects vary from day to day, that catecholamine drugs make the response to aesthetics more consistent, and thus investigations are planned to reduce day to day variability with autonomic blocking drugs.